Electric furnace



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Filed August 8,. 1925 2 Sheets-Sheet 1 Oct. 26 1926.

L. SAT GHWELL ELECTRIC FURNACE Filed August a; 1925 2 Sheets-Sheet 2 Patented on. 26, 1926.

UNITED STATES.

PATENT OFFICE.

L%NARD SATCHWELL, OF SLO'UGH, ENGLAND,A SSIGNOR T0 JOHN BRIGHTWEN ALEX ANDER, 0F BRIXTON, ENGLAND.

' ELECTRIC summon.

Application filed August 8, 1925, Serial No. 49,071, and in Great Britain October 21, 1924. I

This invention relates to improvements in furnaces or chambers heated by the electric resistance method and has for its object to nected together for rotation whereby to rotate the drum or container.

The invention is illustrated by way of example in the accompanying drawings. Figs. 1 and 2 arelongitudinal and transverse sections respectively of a heating chamber constructed in accordancewith the invention. 1

In the drawings the same reference characters indicate like parts.

Referring to the drawings, 0 is the heating element of the furnace or chamber, which is in the form of a split tube connected by leads 6 with the, secondary b of'a transformer, of which a denotes the core. (1 indicates a lagging of low thermal conductivity. The primary coil of the transformer may be suitable for an ordinary supply voltage and the ratio of transformation may be such as is suitable for providing heating currents of large value for the heating elements. The leads 6 which also can-be .conveniently arganged to act as supports should be of low resistance value in comparison with the heating element 0. d represents the outer casing of the furnace.

The furnace is constructed to accommodate a cylindrical drum '71. adapted to contain the articles or material to be heated, and bearing upon rotatable shafts f which are mounted on bearings g and which extend within, and protrude a considerable distance beyond, the furnace, said shafts" f being mechanically connected together by means of sprockets i and a chain k. .As will be understood, when the shafts fiare rotated by hand or by an electric drive, the drum h p is rotated by friction from the shafts f.

The portions of the shafts f which pro- ,trude from the furnace may serve as guides for the drum h in introducing it into the furnace, thereby insuring alignment of the drumv h with the single turn coil heating elements a. entry and withdrawalof the drum h the In order further to facilitate whole structure (furnace, shafts and transformer) may be arranged to rock on a central point sothat, when it is desired to cause the drum to enter'the furnace, the whole structure may be tilted so that the drum will move into its heating position alon the shafts when they are rotated, and, in or or to withdraw the drum after completion of the process, the structure maybe tilted in the opposite directionso that the drum will move outwards by gravity when'theshaf'ts are rotated. J l' When the 'drum is being heated, the shafts may beoccasionally rotated to insure uniform distribution of heat throughout the drum "or to'insure contact, for example, of. the articles to be sherardized with zincdust.

The'drum or container or/and material forms a secondary of another transformer, of which the lining of the furnace constitutes the primary.

The outer casing of the -fur-- nace may, if desired, be of iron of suc'h -pro-, 4

portions as will reduce the reluctance of the magnetic circuit of which the container forms a part. 7

I claim An electric furnace including a container for the material to be heated, said container enclosed by a split tube constituting a single turn conductor, providing a circumferential path for the current, and rotary, shafts freely su porting said container between them,

su stantially aseand scribed.

In testimony whereof I have signed my, name to this specification.

LEONARD sA'rcHWELL.

or the purpose 

